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Post Info TOPIC: Care of LFP
Reed


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Care of LFP
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Temperatures got down to 24 F (-5 C) and charging LFP at temperatures below 0 C will supposedly cause degradation of LFP cells. Have put a remote thermometer ($18 US at any hardward store) in same compartment as the battery suite. It only got down to 40 F (5 C) due to fairly good insulation (walls are about 2.5 cm of foam). Have put 12 V receptacles in compartment and would use a 30 W bulb in a mechanic's inspection lamp if it got below 2 C. The inverter etc are in same compartment and may help keep things warm

We have a fifth wheel and the front of compartment is shaded by the overhang. There are three panels which can give quite good cross ventilation. LFP degrades at temperatures variously stated from 46 C and up. Never plan to be anywhere in such temperatures. However, the inverter can give off a lot of heat when running the Dometic power hog air-conditioner (1750 W) off battery suite/solar panel combination. So have 12 V receptacles (aka auto cigarette lighters) in compartment and can use 12 V fans (1 amp = 12 W) to increase cross ventilation.

Inverter is friend in cold weather and enemy in hot weather

Reed and Elaine



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PeterD


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What is this LFP?

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PeterD
Nissan Navara D23 diesel auto, Spaceland pop-top
Retired radio and electronics technician.
NSW Central Coast.

 
Brenda and Alan


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Peter LFP are lithium iron phosphate cells (LiFePo4).

Thanks for that info Reed. I was not aware of these tight temp ranges so will look into it a bit further as we run a 200 Ah 12V LiFePo4 system. At the current Aust. price for such cells I wouldn't want to compromise their life span.

Alam



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Santa


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lithium iron phosphate (LiFePO
4) battery, also called LFP battery.smile

https://en.wikipedia.org/wiki/Lithium_iron_phosphate_battery



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Cheers,

Santa.

Moonta, Copper Coast, South Aust.
Reed


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l.jpgIt should be easy to keep battery suite temperatures above 0 C and below 49 C. The main thing with the higher temperature is to have a ventilated battery box. The peripherals can generate a lot of heat. Attached is photo of the front bay with two of the LFP batteries (each is four CALB cells in series) shown and the electrical system under construction. These can provide a lot of heat



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Reed


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Alan

Price of LFP is probably about the same in US and Australia. The use of LFP is far more prevalent in Australia. Have noted that a number of caravan manufacturers now offer LFP. Only the top end Liberty Lady Prevost conversions ($1.8 M US) do this.

Sons and families are in Las Cruces, New Mexico at daughter's place for Thanksgiving. Asked grandson if he could put in a Halogen lamp to heat the battery compartment. He said "Grandpa, I did that last year." I said it doesn't seem to be working. He showed me the ON/OFF switch. "Oh!"
Reed and Elaine

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Brenda and Alan


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Reed getting of topic a bit but current price for cells in Aust. is running at around $1760 per 12V 200 Ah set. How does this compare to US prices.

Alan



-- Edited by Brenda and Alan on Friday 27th of November 2015 07:25:01 AM

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Reed


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Brenda and Allan

This price is fairly similar for top end.

We have Manzanita Micro www.manzanitamicro.com/home

Their batteries are composed of Chinese Aviation Lithium (CALB) cells that are fabricated into an aluminum box. These are designed for the Electric Vehicle folks. The below is from their site

"...This is a complete solution for all of your battery box needs. Available in 180Ah packs. Includes: 4 Lithium Ion Cells, Aluminum Battery Box, Lexan Top, Fully Assembled Reg Deck, All necessary hardware, and Regulator..
The battery box is 8" wide, 12.5" long, 13.5" tall (without lugs). Total weight with 180Ah cells is 63 lbs/ 28.5 kg..."

Each battery (180 amps at 12 V nominal) is $1564 US. They charge $620 US for the box and regulator alone without the cells.

We have been quite happy with them, but son who is in solar business, believes that ones designed for RV trade may become available

AM Solar has the best reputation for installing solar systems in US but they are not terribly sophisticated. They just started installing LFP and their prices are far high for far less. From their site www.amsolar.com/

"...We banded two 100Ah cells together to give you a 3.2 Volt/200Ah segment called a "super cells". It will take four of these segments to make a 12.8 Volt/200Ah battery. By giving you four segments, you can lay them out in different patterns to better fit your available space. Some of the possible configurations are seen in the photo to the left. When you get them laid out like you want, you simply series out the four segments to get your final 12.8 Volt/200AH battery..."
"...Price: $1,899.00 US
So no box and no regulator etc for $300 US more. They are not even packaged.

Stark Power charges $959 US for a 100 amp-hr at 12 V nominal. www.starkpower.com/

We have four of the Manzanita Micros set in series for 180 Amp-hrs at 48 V (nominal) or 54 V at full charge. So far, they seem to be the best and most sophisticated battery suites available. Our son designs and fabricates solar/battery systems for businesses, homes, and power companies and the job he did is sophisticated. I can write to you on system if you are interested.

If you are paying $1800 Aus for 200 Amp-hours, you are doing much better than here. If you are paying $1800 US than it is comparible

Reed and Elaine


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